My boyf and I aren't too serious about Halloween, but the idea of dressing as SNL's Two A-Holes is too brills to ignore.
Another possible costume for him is Billy Mays! You know, that guy who pushes Oxy Clean and is constantly YELLING? Some insanely dark beardage and a loud voice would complete the costume.
My final idea is genius for its simplicity. If all else fails, just write "Not Penny's Boat" on the palm of your left hand. I just recommend staying above water while doing so. R.I.P. Charlie!